Frequencies for first 10,000 rows of mod_year variable in vehicle dataset :

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
         24 |          1        0.01        0.01
         26 |          1        0.01        0.02
         36 |          1        0.01        0.03
         40 |          1        0.01        0.04
         47 |          1        0.01        0.05
         50 |          3        0.03        0.08
         51 |          1        0.01        0.09
         52 |          4        0.04        0.13
         53 |          3        0.03        0.16
         54 |          3        0.03        0.19
         55 |          2        0.02        0.21
         56 |          3        0.03        0.24
         57 |          3        0.03        0.27
         58 |          4        0.04        0.31
         59 |          4        0.04        0.35
         60 |          6        0.06        0.41
         61 |          3        0.03        0.44
         62 |         13        0.13        0.57
         63 |         26        0.26        0.83
         64 |         28        0.28        1.11
         65 |         48        0.48        1.59
         66 |         52        0.52        2.11
         67 |         44        0.44        2.55
         68 |         67        0.67        3.22
         69 |         73        0.73        3.95
         70 |        103        1.03        4.98
         71 |        111        1.11        6.09
         72 |        162        1.62        7.71
         73 |        219        2.19        9.90
         74 |        190        1.90       11.80
         75 |        203        2.03       13.83
         76 |        302        3.02       16.85
         77 |        340        3.40       20.25
         78 |        468        4.68       24.93
         79 |        507        5.07       30.00
         80 |        460        4.60       34.60
         81 |        437        4.37       38.97
         82 |        429        4.29       43.26
         83 |        402        4.02       47.28
         84 |        615        6.15       53.43
         85 |        718        7.18       60.61
         86 |        712        7.12       67.73
         87 |        743        7.43       75.16
         88 |        776        7.76       82.92
         89 |        847        8.47       91.39
         90 |        547        5.47       96.86
         91 |         29        0.29       97.15
         99 |        285        2.85      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016